In general, data processors implement floating point operations using subroutines constructed using only integer instructions and flow control instructions. In order to provide greater computing power for those applications requiring significant numbers of floating point operations, some data processors implement in hardware the essential floating point instructions, such as addition, subtraction, multiplication and division. Some even provide special floating point instructions such as square root.
Most commonly, these floating point instructions are directly integrated into the data processor. On the other hand, in some data processors the floating point instructions are provided in a separate numeric processor or "coprocessor" which cooperates with the main processor to execute the floating point instructions. Examples of this latter form of numeric processor are shown in U.S. Pat. Nos. 4,270,167 and 4,509,116.
In contrast to the basic floating point instructions, support for the transcendental functions, such as sine/cosine, logarithms and exponentials, is almost always provided using subroutines constructed using the integer and flow control instructions, and, if available, the floating point instructions. In at least one of the prior art numeric processors, the Intel 8087 shown in U.S. Pat. No. 4,509,116, instructions are provided to support restricted forms of certain of the transcendentals. However, in order to perform the other forms of these selected transcendentals, as well as the other transcendentals, a "software envelope" must be provided. No known numeric processor directly supports even a significant subset of the transcendental functions.
In view of the rapidly expanding requirement for floating point arithmetic in many fields, it is desirable that a numeric processor be provided which can directly support the IEEE Standard for Binary Floating-Point Arithmetic, ANSI/IEEE Std. 754-1985. It is also desirable that a numeric processor be provided which is able to support transcendental functions consistent with the IEEE Standard without a software envelope.